Chapter 4 - Quadratic Functions and Equations - Mid-Chapter Quiz - Page 224: 21

$3x^2(x^2-4x-9)$

The GCF is $3x^2$, every term is divisible by 3 and $x^2$. So, this will first look like $3x^2(x^2-4x-9)$ We need to see if there are two numbers that add to -4 and multiply to -9, and there are not. There is no GCF in the parenthetical expression)